Stabilization of vinyl resins and compositions produced thereby



Patented n. so, 1931 2,075,543

UNITED STATES PATENT OFFICE has STABILIZATION OI VINYL BEGINS ANDCOMPOSITIONS PRODUCED Marion 0. Reed and Frasier Grofl, Lakewood. Ohio,assignors, by means assignments. to llnioncarbide and Carboncorporation, a corporation oi New York No mawins. Application July 1a,1.84, Serial No. 184,508

18 Clalms. (O1- 360-!) The present invention relates to the productionsuch compounds may be mentioned basic lead of both heatand light-stablesynthetic resins carbonate, barium succinate, cadmium palm-itate. andcompositions containing the same. More escalcium lactate, calciumlactic-pho ph t le peoially it involves the manufacture oi vinylresadipate, lead bensoate, lead tartrate, lead and 5 ins andcompositions wherein certain stabilising manganese palmitates, sodiumabietate, and lead agents are incorporated, preierably duringiormaacetate. tion oi the resin or composition, ior the purpose Some oithese compounds are slig tly 809 oi rendering them stable toward heatand light. to others in their ability to import to resins conand oipreventing or retarding the destruction oi taining them resistance todiscoloration by sunthose valuable properties oi the resins adaptinglight. This ability bears no relation to the propthem ior their ordinarycommercial uses. erties oi these compounds as heat-stabilizers.

Many methods are already well known ior the The soaps oi certain metals,such as copper production oi resinous bodies by the partial or oleate,do not iunction satisiactorily as heat complete polymerization oi avinyl compound or stabilizers ior these resins, but serve, however,

5 oi a mixture oi two or more vinyl compounds. to increase thelight-resistance oi the resins, even Such resins and compositionscontaining the same when used in minute amounts, in unstabilized have awide held 01' usefulness in the production resins or in those resinsstabilised against deoi lacquers, paints, varnishes, adhesives. andothterioration by heat with heat-stabilising soaps or or coating andimpregnating compositions. They their equivalent tor the W.

also may be employed in the solid state as the Those metal soaps orsalts which are particubases i'or molding compounds and plastic comlarlyeiiective are easily dispersed or dissolved in positions oi variouskinds. the molten or plastic vinyl resin, or in a solution The vinylresins produced by processes in use or dispersion thereoi in a solventsuch as toluene prior to this invention generally have possessed oracetone.

the objectionable property oi being relatively un- The cadmium soaps,while as a rule somewhat stable to heat and/or light, particularly tosunless eiiective as heat-stabilizers for preventing light. Therefore.such resins and the composidiscoloration oi the resin than are thecorreiions containing them irequently tend gradually sponding leadsoaps, are highly satisiactory ior to discolor in the course oi the heattreatment rethe purpose, and are usually preierred to calcium quired iormolding them or ior incorporating soaps. The metal laurates alsogenerally are althem into liquid coating compositions, or they iective,as are the corresp d metal salts f develop color subsequent theretoduring exposure most of the weak acids. The man anese so -P oi the sameto natural or artificial light and heat are strongly resistant todiscoloration by heat in the ordinary course oi their use. but aresomewhat colored themselves.

35, The present invention is based upon the dis- The metallic soaps an881i! 0! Wea 18 11 covery that resinous polymerization products of acidsoi the present invention definitely retard the nature oi those describedmay have th ir the liberation of hydrogen chloride that is assostabilitytoward heat and light greatly increased ciated with resin decomp n dloraby the incorporation therein, either during their tion- Thstabilizer! Preferably a st manuiacture or subsequent thereto. oi smalltially neutral or-siishtly basic. olthoush the resin amounts of certainmetallic organic compounds, mixture may be rendered more alkaline, whenespecially oi metal soaps oi saturated. unsatdesired, by theintroduction oi iree alkaline oxurated and substituted iatty acids. suchas the ides. hyd or other alkaline mpou ds. stearates, oleates,linoleates, rlcinoieates. palmi- I i probable that as the resin v l p an5 tates, abietates, oxidised linoleates and ricinoletendency toward p iion. accomp n e y ates, acetylated ricinoleates. and laurates oi the theformation oi an acid, the stabilizing soap alkaline earth metals, thealkali metals, cadmipresent correspondingly is reactive therewith to in,lead, manganese and antimony. neutralize the acid, as well as its eiiectupon the Among the most eflective oi these stabilizers resin. are thelead, manganese, cadmium, and alkalina- The metal soaps employed may bein the nature earth salts oi the above-mentioned fatty acids. oioxidized, acetylated or other soap such as However, the correspondingmetal salts oi other those prepared by reacting a solution of a saltiatty acids and oi other weak organic acids also oi the metal and awater-soluble soap derived function very satisfactorily for increasingthe from an oxidized or blown linseed oil, blown heatand light-stabilityoi these resins. Among castor oil. or an acetylated ricinoleate.Superior light-stabilizing eifects are obtained by soaps of these blownor oxidized oils.

The stabilizing compounds of the present in- 5 heat-stabilization oi'polymerized resins.

possess light-stabilization properties in varying degree. Therefore,they often may be used advantageously in conjunction with other soaps.esters, or other stabilizing substances for that purpose. Where certainesters, such as butyl salicylate or methyl salicylate, are incorporatedin vinyl resins for light-stabilization of the latter, there sometimesmay be produced in the resin a slight bluish haze. The introduction ofvery small amounts of a soap or organic salt of the present invention.such as strontium oleate and/or sodium oleate, facilitates theproduction of a clear resin.

Certain light-stabilizers such as urea are sometimes diii'lcult todisperse properly in vinyl resins. The addition of as small an amount as.196 or less of a sodium or other alkali metal soap. such as the oleate,stearate, linoleate, or ricinoleate, eii'ectively disperses the urea inthe resin, while 2 preserving the light-stabilizing eii'ect oi theformer.

The light-stabilizing action of certain metal soaps oi the presentinvention which are especially selected for heat-stabilization. may begreatly improved by the addition to the resin of even extremely smallamounts. less than .i%, of certain metal soaps not themselves suitableheat-stabilizers. In one instance, a vinyl resin that had beenstabilized toward heat by the addition of 1% of lead oleate. had itsstability toward sunlight substantially doubled by the addition thereto01' .01% of copper oleate. although the latter has little, if any,heat-stabilizing actio The soaps may be added to the resin in the formof a mixed soap, such as mixed cadmiumlead stearates, or a mixture oflead oleate and stearate: or the respective soaps may be introduced intothe resin successively.

The stabilizing agent may be uniformly incorporated with thepolymerization product to be stabilized in any suitable manner thatinsures an intimate mixture of these materials. Preferably this iseii'ected by mixing the dry resin and stabilizer in a masticator or onheated differential rolls. Proper mixing generally may be secured withinfifteen minutes or less on rolls heated to from around 100 C. to around110' C.

The stabilizer may alsobe incorporated in the resin in the presence ofacetone or other suitable solvent, or in the presence of a iiuidnon-solvent for the resin. In such case the metal soap preferably isdissolved or dispersed in the solution or dispersion oi' the resin, andthe resin and stabilizer are then precipitated in intimate admixture soby introducing water into the solution. The wet precipitate (generallyafter washing with water) may be dried in a drier or on diflerentialrolls heated to around 110 C. to 115 C. A Vinyl resin produced by theconjoint polymerization of a n5 mixture containing 85% vinyl chlorideand 15% vinyl acetate and stabilized in the wet way mentioned above with.8% of alkaline calcium stearate showed no darkening after severalmonths ex posure to light.

The amount of stabilizer employed may vary within rather wide limits.depending upon the nature oi the stabilizer and the physical andchemical properties or the polymerization product to be stabilized. Anamount of the stabilizer within the range from .5% and 3% oi the weightaromas of the product to be stabilized. and generally around 1% thereof,provides satisfactory stabilization, while preserving the desirablephysical properties oi the product. These soaps or salts may be employedin the resins in amounts greater than 3%. Under such conditions they mayalso function as plasticizers, and for modifying the hardness. toughnessand other physical properties of the resin or resinous composition. Evenwhen used in the smaller amounts named above. the soaps exert a slightplasticlzing action. and they also serve as lubricants, facilitating theready processing of the resin and the easy removal thereof from molds.calender rolls, and the like.

Among the polymerization products especially adapted to be stabilizedagainst the action of heat and/or light by the present invention arethose produced by the more or less complete polymerization oi vinylhalides, and of mixtures of vinyl halides and vinyl esters of aliphaticacids. or by the conjoint polymerization of mixtures of such compounds.Preferred resins oi' the latter type may be prepared from mixtures ofvinyl chloride and vinyl acetate, containing from about 60% to about ofvinyl chloride. These resins may have incorporated therein the usualplasticizers, fillers, and coloring materiais.

The following examples will illustrate the inventiou:

Example 1 A plastic mass of a vinyl resin formed by the conjointpolymerization of a mixture of about 85% vinyl chloride and about 15%vinyl acetate, which had been precipitated with water from an acetonesolution oi the resin, had intimately incorporated therein 1% or itsweight of lead oleate produced by reacting 2 mols of oleic acid with 1mol. of litharge. A somewhat lighter grade of lead oleate especiallyadapted for the stabilization of these resins may be made by reactingone mol. of lead acetate with 2 mols of sodium oleate in water solution,followed by the washing of the resultant lead oleate. first with waterand then with methanol. The lead oleate was milled into the resin ondiii'erential rolls heated to 6., yielding a clear, pale amber product.many times as resistant to a heat of around C. and higher, and to theaction of iisht as is the same resin when unstabilized. The resinretained its valuable properties of toughness and elasticity. and wasfree from obiectionable brittleness under normal conditions of its use.

Example 2 A vinyl resin produced by the conjoint polymerization of amixture of about 85% of vinyl chloride and about 15% of vinyl acetatehad 1% of its weight of cadmium laurate milled into it over aperlod oififteen minutes on rolls heated to 100 C. The milled resin mixture was avery pale amber color, and was many times as resistant to prolongedexposure to a temperature of 125 C. as was the same resin unstabilized.It was also resistant to the action of sunlight.

Example 3 100 parts by weight of remaining site:-

accuses those named in Example 2. The resultant resin was stable towardlight and to heat applied to the resin in subsequent molding operationsduring utilization of the resinous product.

Decomposition actually occurring within an unstabilized resin such as apolymerized vinyl chloride resin, may be definitely stopped and thecolor of the resin definitely improved so as to yield a much lighterproduct by milling therein around 1% or more 01 calcium stearate orother stabilizer of the present invention, even while the same isexposed to elevated temperatures as high as 140 C. or employed may berendered somewhat alkaline with calcium hydroxide.

By the practice the present invention bodies and coatings of vinylresins can be produced which are suitably strong, hard, and tenacious toadapt them for the usual commercial uses for these resins, and whichresins are highly resistant to the destructive action of heat and light.

The invention is susceptible of modification within the scope of theappended claims.

We claim:

1. A heatand light-resistant polymerization product 0! at least onevinyl ester, including a vinyl halide, which product contains a smallamount of a metal soap having a metallic radical selected from the groupof metals consisting of the alkali metals, the alkaline earth metals,cadmium, lead and manganese.

2. A heatand light-resistant polymerization product of at least onevinyl ester, including a vinyl halide, which product contains from about/2% to around 3% of a metal soap having a metallic radical selected fromthe group of metals consisting of the alkali metals, the alkaline earthmetals, cadmium, lead and manganme.

3. A heatand light-resistant polymerization product of at least onevinyl ester, including a vinyl halide, which product contains a smallamount of a mixture of metal soaps, including a lead soap and a metalsoap adapted to still further increase the light-stability oi the saidproduct.

4. A heatand light-resistant polymerization product of at least onevinyl ester, including a vinyl halide, which product contains a smallamount of a mixture of metal soaps including a lead soap, and a coppersoap adapted to increase further the light-stability oi. the saidproduct.

5. Process 01 producing heatand light-resistant resinous polymerizationproducts of vinyl esters, which comprises intimately mixing apolymerization product of at least one vinyl ester, in-

. eluding a vinyl halide, and a small amount 0! a metal salt of a weakorganic acid having its metal radical selected from the group of metalsconsisting of the alkali metals, the alkaline earth metals, cadmium,lead, and manganese, and having its acid radical selected from the groupconsisting of stearic acid, oleic acid, linoleic acid, ricinoleic acid,lauric acid, palmitic acid, abietic acid, oxidized linoleic acid,acetylated ricinoleic acid and oxidized ricinoleic acid.

6. Process of producing heatand light-resistant resinous polymerizationproducts of vinyl esters, which comprises intimately mixing apolymerized vinyl ester and a small amount 0! a metal soap having itsmetal radical selected from the group of metals consisting of lead,manganese, cadmium, the alkali metals, and the alkaline earth metals,and having its acid radical selected 75 from the group consisting oistearic acid, oleic higher. The calcium stearate cium, manganese,

acid, linoleic acid, ricinoleic acid, lauric acid, palmitic acid,abietic acid, oxidized linoleic acid, acetylated ricinoleic acid, andoxidized ricinoleic acid.

7. Process oi dispersing a light-stabilizing organic compound .in aresinous polymerization product oi at least one vinyl ester, including avinyl halide, while concurrently improving the heat stability oithe-product, which comprises mixing with the latter and the saidcompound at an elevated temperature a small amount of an alkali metalsoap.

8. Process 0! producing heatand light-resistant resinous polymerizationproducts of vinyl esters, which comprises intimately mixing together apolymerized vinyl ester and a small amount of a heat-stabilizingcompound 01 a metal selected from the group consisting of lead, calthealkali metals, and the alkaline earth metals, with a weak organic acidselected from the group consisting of stearic acid, oleic acid,ricinoleic acid, linoleic acid, lauric acid, palmitic acid, abieticacid, oxidized linoleic acid. acetylated ricinoleic acid and oxidizedricinoleic acid, and iurther mixing with the said vinyl compound lessthan .l% of its weight or a copper soap.

9. Process of producing heatand light-resistant resinous polymerizatlonproducts of vinyl esters, which comprises dispersing a metal soap in asolution of a polymerization product of at least one vinyl ester in awater-soluble organic solvent, co-precipitating the said product and themetal soap in intimate intermixture, washing the precipitated resin, anddrying the same, the said soap having its metallic radical selected fromthe group of metals consisting of lead, manganese, cadmium, the alkalimetals, and the alkaline earth metals, and having its acid radicalselected from the group consisting of stearic acid. oleic acid, linoleicacid, ricinoleic acid, lauric acid, palmitic acid, abietic acid,oxidized linoleic acid, oxidized ricinoleic acid, and acetylatedricinoleic acid.

10. A heatand light-resistant polymerization product of at least onevinyl ester, including a vinyl halide, which product contains a smallamount of at least one metal soap having a metallic radical selectedfrom the group consisting of the alkali metals, the alkaline earthmetals, cadmium, lead and manganese, and having its acid radicalselected from the group consisting of stearic acid, oleic acid.ricinoleic acid, linoleic acid, lauric acid, palmitic acid, abieticacid, oxidized linoleic acid, oxidized ricinoleic acid and acetylatedricinoleic acid.

11. A heatand light-resistant polymerization product of at least onevinyl ester, including a vinyl halide, which product contains an esteradapted to increase the stability of the said product toward light, anda heat-stabilizing metal soap having a metallic radical selected fromthe group consisting oi. the alkali metals, the alkaline earth metals,cadmium, lead, and manganese, and having its acid radical selected fromthe group consisting oi stearic acid, oleic acid, ricinoleic acid,linoleic acid, lauric acid, palmitic acid, abietic acid, oxidizedlinoleic acid. oxidized ricinoleic acid and acetylated ricinoleic acid.

12. A heatand light-resistant polymerization product oi at least onevinyl ester, including a vinyl halide, which product contains hutylsalicylate, adapted to increase the stability 01 the seid roduct towardiisht. and a small amount oieic acid. ricinoieie acid. linoieic acid.ieuric o! s. feat-stabilizing metal soap having a metallic acid.neimitic scid, lbietic acid. oxdined linoieic radical selected iron: thegroup consisting oi the acid, oxidised ricinoleic acid lad lcetyietudaiksii metals, the alkaline earth metals, cadmium. ricinoieic acid.

5 lead and manganese. and having its acid radical MARION C. REID. ii

eeiected from the group consisting of stearic acid. RAZER GROW.

CERTIFICATE OF CORRECTION Patent No. 2,075,543. March 30, 1937.

MARION C. REED, ET AL.

the Patent Office.

Signed and sealed this 11th day of May, A. D. 1937,

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

seid roduct toward iisht. and a small amount oieic acid. ricinoieieacid. linoieic acid. ieuric o! s. feat-stabilizing metal soap having ametallic acid. neimitic scid, lbietic acid. oxdined linoieic radicalselected iron: the group consisting oi the acid, oxidised ricinoleicacid lad lcetyietud aiksii metals, the alkaline earth metals, cadmium.ricinoieic acid.

5 lead and manganese. and having its acid radical MARION C. REID. ii

eeiected from the group consisting of stearic acid. RAZER GROW.

CERTIFICATE OF CORRECTION Patent No. 2,075,543. March 30, 1937.

MARION C. REED, ET AL.

the Patent Office.

Signed and sealed this 11th day of May, A. D. 1937,

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

